There are many conventional switches known in the art for sea based applications. These conventional switches include, but are not limited to, pressure switches available from Global Ocean Design of San Diego, Calif. under part number G-117 and G-120. The operational state of the pressure switch may be selected as: a first operational state in which the switch is “on” at the sea's surface and “off” below the sea's surface; or a second operational state in which the switch is “off” at the sea's surface and “on” below the sea's surface. The pressure switches typically trigger between 2-3 atm gauge pressure (or stated differently at 100's of feet below the sea's surface). The pressure switch has a relatively large tolerance. For example, in some cases, the pressure switch has a tolerance of ±100 feet, i.e., the pressure switch will trigger between a 100 or 200 foot range (e.g., 200-300 feet or 200-400 feet below the sea's surface). This relatively large tolerance range is undesirable in many applications. Also, the pressure switch is unreliable since it fails or breaks within a short period of time (e.g., days) after being submerged in water. The failure is often caused by the internal components of the pressure switch. These components can include a sliding piston spring actuator. The triggering is achieved by: the depression of a diaphragm formed of an elastomeric material as a result of pressure being applied thereto from sea water submersion; and the application of a pushing force by the diaphragm to the sliding piston spring actuator.
Some of the conventional pressure switches are modifiable to meet certain criteria for given applications. However, the modified pressure switches are unreliable and inaccurate in certain applications due to complex mechanisms (i.e., pistons and springs) and the failure of elastomeric materials to activate the switch in shallow depths.